The present invention relates generally to fluid filters and more particularly to fluid filters used in closed fluid circulating systems.
Fluid filters are frequently used in closed fluid circulating systems. Such systems will typically consist of a supply line, a return line, a pump, and a reservoir for the excess fluid. A filter housing containing a filter element(s) is typically located in or on a branch of the supply line so that the fluid is filtered as it circulates in the system. A familiar example of such a closed system is the oil circulation system of an automobile.
In most industrial applications, the filter housing and filter element are not formed as an integral unit, and replacing the filter element inevitably creates several potential problems. The supply line connections to the filter housing are open and exposed, permitting vapor and liquid leakage. This can result in the possible contamination of the surrounding environment, and adversely affect the health of any operating or maintenance personnel in the area. The filter housing itself must also be drained and cleaned, providing both additional opportunities for leakage and further complicating the filter replacement process.
An additional waste-related problem encountered during filter replacement results from the concentration of waste materials within the filter due to the filtering operation itself. These concentrated wastes remain within the filter housing along with some remaining fluid, and provide additional opportunities for leakage.
These various leakage problems are only a nuisance to be cleaned-up when oil leaks from an automotive oil system; however, it can be dangerous, even deadly where the circulating system contains toxic and ultra-hazardous chemical wastes, which are in turn further concentrated by the filter.
The use of such toxic materials in the workplace is subject to a number of federal and state occupational safety regulations, which in turn cause the filter replacement procedure to be both cumbersome and expensive. Moreover, the environmental rules and regulations require that the used filter elements and contaminated clean-up materials be sealed in a container and disposed of in a safe manner.
The vapor deposition process used to manufacture many of the electronic components being used today is a prime generator of a fluid that is contaminated with deadly poisons. The various substrate layers are applied as vapors under high temperatures and strong vacuums. The lubricant used to seal and lubricate the vacuum pump soon becomes contaminated with toxic, abrasive, and corrosive wastes that must be removed to avoid damage to the pump. A filter is used to clean this lubricant, and consequently concentrates all of these hazardous materials within the filter and filter housing. The removal and disposal of the filter, under the prior systems, was a difficult and dangerous job.